The GN-XIII is a GN Drive Tau-equipped mobile suit and a descendant of the GNX-603T GN-X utilized by the UN Forces against the Celestial Being. The GN-XIII is based on the GNX-607T GN-XII, the GN-X's successor, and since older models of the GN-X series can be upgraded into newer models by switching out parts, this implied that some of the GN-XIII units are retrofitted GN-XII units. Deployed in AD 2312 as the mainstay mobile suit of the Earth Sphere Federation Forces and the autonomous peacekeeping force A-Laws, the GN-XIII is a general-purpose machine like its predecessors and still relies on overwhelming the enemy through superior numbers even as it is mainly deployed for peacekeeping purposes. With the use of GN Drive Tau-type mobile suits currently monopolized by the Earth Sphere Federation government, the GN-XIII is considered an overwhelmingly powerful machine for most opponents, though an exception is the reborn Celestial Being and its new Gundams, but the GN-XIII still has an edge in terms of numbers.